1. Welcome to 4Runners.com!

    You are currently viewing as a guest! To get full-access, you need to register for a FREE account.

    As a registered member, you’ll be able to:
    • Participate in all 4Runner discussion topics
    • Communicate privately with other 4Runner owners from around the world
    • Post your own photos in our Members Gallery
    • Access all special features of the site

Replaced cats, still getting CEL please help

Discussion in '4th Gen 4Runners (2003-2009)' started by rollinhorns, Jul 3, 2015.

  1. Jul 3, 2015 at 9:42 AM
    #1
    rollinhorns

    rollinhorns [OP] New Member

    Joined:
    Jul 3, 2015
    Member:
    #744
    Messages:
    1
    Gender:
    Male
    First Name:
    Ryan
    Vehicle:
    08 4Runner SR5 4x4
    ok guys, so I was getting the dreaded P0420 and P0430 codes on my wife's car (110k miles). To rule out other culprits, I took it in to a local mechanic to scan the voltage across the O2 sensors to make sure it wasn't them. Sure enough it wasn't, and I was told both cats are bad. Guy wanted to charge me $3k so naturally I said no thanks. Bought some OEM cats online and replaced them myself (horrible horrible job).

    Anyways, CEL goes off for about a week before it returns (yes very upsetting). So I take it to autozone and the code reader spits out P2195 (bank 1 O2 sensor or MAF stuck lean) and P0171 (air/fuel mix lean on bank 1).

    Does anyone have any input on this? Sounds to me like an O2 sensor issue but it's odd because when I took the car in for the voltage scan, everything looked ok sensor wise.

    Appreciate any and all advice!
     
  2. Jul 3, 2015 at 8:01 PM
    #2
    ThorInc

    ThorInc New Member

    Joined:
    Sep 28, 2014
    Member:
    #279
    Messages:
    5
    Gender:
    Male
    Vehicle:
    1997 4Runner SR5 3.4L
    I would reset the codes and see if it comes back.
     
    Bob likes this.
  3. Dec 28, 2015 at 10:47 AM
    #3
    Ohmslaw

    Ohmslaw New Member

    Joined:
    Dec 28, 2015
    Member:
    #1330
    Messages:
    3
    Gender:
    Male
    First Name:
    Scott
    Vehicle:
    04 SR5
    Those codes look familiar. I believe that I had similar codes and also the VSC TRAC fault light on my dash, which would disable the traction control. I reset the codes and used the Zero Point Calibration routine to reset the VSC TRAC system, but it continued to come back after a month or two. Replaced the O2 Sensors and the problem went away. This is a cheap and quick fix, as each O2 sensor is about $70 vs the 3k cat replacements. It seems that they can start to get weak work marginally. They also can cause other weird, seemingly unrelated problems. I am very leery about replacing items, just because a code comes up. A lot of times, the code is just a symptom of the other, real, problem.
     

Products Discussed in

To Top